[lld] r299600 - Return Optional<uint64_t> from readInteger instead of returning just success/failure.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Wed Apr  5 18:22:11 2017
New Revision: 299600

URL: http://llvm.org/viewvc/llvm-project?rev=299600&view=rev
Log:
Return Optional<uint64_t> from readInteger instead of returning just success/failure.

Modified:
    lld/trunk/ELF/ScriptParser.cpp

Modified: lld/trunk/ELF/ScriptParser.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ScriptParser.cpp?rev=299600&r1=299599&r2=299600&view=diff
==============================================================================
--- lld/trunk/ELF/ScriptParser.cpp (original)
+++ lld/trunk/ELF/ScriptParser.cpp Wed Apr  5 18:22:11 2017
@@ -762,38 +762,38 @@ uint64_t static getConstant(StringRef S)
   return 0;
 }
 
-// Parses Tok as an integer. Returns true if successful.
-// It recognizes hexadecimal (prefixed with "0x" or suffixed with "H")
-// and decimal numbers. Decimal numbers may have "K" (kilo) or
-// "M" (mega) prefixes.
-static bool readInteger(StringRef Tok, uint64_t &Result) {
+// Parses Tok as an integer. It recognizes hexadecimal (prefixed with
+// "0x" or suffixed with "H") and decimal numbers. Decimal numbers may
+// have "K" (Ki) or "M" (Mi) suffixes.
+static Optional<uint64_t> parseInt(StringRef Tok) {
   // Negative number
   if (Tok.startswith("-")) {
-    if (!readInteger(Tok.substr(1), Result))
-      return false;
-    Result = -Result;
-    return true;
+    if (Optional<uint64_t> Val = parseInt(Tok.substr(1)))
+      return -*Val;
+    return None;
   }
 
   // Hexadecimal
-  if (Tok.startswith_lower("0x"))
-    return !Tok.substr(2).getAsInteger(16, Result);
-  if (Tok.endswith_lower("H"))
-    return !Tok.drop_back().getAsInteger(16, Result);
+  uint64_t Val;
+  if (Tok.startswith_lower("0x") && !Tok.substr(2).getAsInteger(16, Val))
+    return Val;
+  if (Tok.endswith_lower("H") && !Tok.drop_back().getAsInteger(16, Val))
+    return Val;
 
   // Decimal
-  int Suffix = 1;
   if (Tok.endswith_lower("K")) {
-    Suffix = 1024;
-    Tok = Tok.drop_back();
-  } else if (Tok.endswith_lower("M")) {
-    Suffix = 1024 * 1024;
-    Tok = Tok.drop_back();
-  }
-  if (Tok.getAsInteger(10, Result))
-    return false;
-  Result *= Suffix;
-  return true;
+    if (Tok.drop_back().getAsInteger(10, Val))
+      return None;
+    return Val * 1024;
+  }
+  if (Tok.endswith_lower("M")) {
+    if (Tok.drop_back().getAsInteger(10, Val))
+      return None;
+    return Val * 1024 * 1024;
+  }
+  if (Tok.getAsInteger(10, Val))
+    return None;
+  return Val;
 }
 
 BytesDataCommand *ScriptParser::readBytesDataCommand(StringRef Tok) {
@@ -820,18 +820,18 @@ Expr ScriptParser::readPrimary() {
   if (peek() == "(")
     return readParenExpr();
 
-  StringRef Tok = next();
-  std::string Location = getCurrentLocation();
-
-  if (Tok == "~") {
+  if (consume("~")) {
     Expr E = readPrimary();
     return [=] { return ~E().getValue(); };
   }
-  if (Tok == "-") {
+  if (consume("-")) {
     Expr E = readPrimary();
     return [=] { return -E().getValue(); };
   }
 
+  StringRef Tok = next();
+  std::string Location = getCurrentLocation();
+
   // Built-in functions are parsed here.
   // https://sourceware.org/binutils/docs/ld/Builtin-Functions.html.
   if (Tok == "ABSOLUTE") {
@@ -921,9 +921,8 @@ Expr ScriptParser::readPrimary() {
     return [=] { return Script->getSymbolValue(Location, Tok); };
 
   // Tok is a literal number.
-  uint64_t V;
-  if (readInteger(Tok, V))
-    return [=] { return V; };
+  if (Optional<uint64_t> Val = parseInt(Tok))
+    return [=] { return *Val; };
 
   // Tok is a symbol name.
   if (!isValidCIdentifier(Tok))
@@ -959,9 +958,8 @@ std::vector<StringRef> ScriptParser::rea
 // name of a program header type or a constant (e.g. "0x3").
 unsigned ScriptParser::readPhdrType() {
   StringRef Tok = next();
-  uint64_t Val;
-  if (readInteger(Tok, Val))
-    return Val;
+  if (Optional<uint64_t> Val = parseInt(Tok))
+    return *Val;
 
   unsigned Ret = StringSwitch<unsigned>(Tok)
                      .Case("PT_NULL", PT_NULL)
@@ -1102,10 +1100,10 @@ uint64_t ScriptParser::readMemoryAssignm
   expect("=");
 
   // TODO: Fully support constant expressions.
-  uint64_t Val;
-  if (!readInteger(next(), Val))
-    setError("nonconstant expression for " + S1);
-  return Val;
+  if (Optional<uint64_t> Val = parseInt(next()))
+    return *Val;
+  setError("nonconstant expression for " + S1);
+  return 0;
 }
 
 // Parse the MEMORY command as specified in: